Methods for enhancing efficiency of bitumen extraction from oil sands using lipids and lipid by-products as process additives

Abstract

In a method for enhancing the efficiency of separation of bitumen from oil sands ore, lipids, lipid by-products, and lipid derivatives are used as process additives for ore-water slurry-based bitumen extraction processes or in situ bitumen recovery processes. These additives act as surfactants reducing surface and interfacial tensions, thus promoting breakdown the oil sands ore structure and resultant liberation of bitumen from the ore. Lipid treatment does not deleteriously affect release water chemistry in bitumen recovery processes, and it does not appreciably affect the fuel value of recovered bitumen. Lipids which may be effectively used as additives include biodiesel, tall oil fatty acids, monoglycerides, vegetable oil, and soap water, and combinations thereof. Lipids may also be used as process additives to enhance the efficiency of clean-up of hydrocarbon-contaminated soils, in the production of bitumen-water or oil-water emulsions, and to enhance the transportability of emulsions such as in pipelines.

What is claimed is: 
     
       1. A method for enhancing recovery of bitumen from oil sands in conjunction with a steam-assisted in situ bitumen recovery process, said method comprising the step of introducing a surfactant consisting of biodiesel into oil sands ore in situ, at a dosage in the range between approximately 50 milligrams and approximately 2,000 milligrams of surfactant per kilogram of bitumen in the ore, wherein the introduction of the surfactant into the oil sands ore is effected by mixing the surfactant into steam being injected into the ore for purposes of the steam-assisted in situ bitumen recovery process. 
     
     
       2. The method of  claim 1 , further comprising the step of adding lime to the oil sands ore in conjunction with the introduction of surfactant, said lime being in a form selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
       3. The method of  claim 2  wherein lime is added to the oil sands ore at a dosage between approximately 30 milligrams of lime per kilogram of oil sands ore and 200 milligrams of lime per kilogram of oil sands ore. 
     
     
       4. The method of  claim 1  wherein the dosage of surfactant is approximately 100 milligrams of surfactant per kilogram of bitumen in the ore. 
     
     
       5. The method of  claim 1  wherein the biodiesel comprises esters of tall oil fatty acids. 
     
     
       6. The method of  claim 5  wherein the biodiesel is a product of esterification of tall oil fatty acids with alcohol. 
     
     
       7. The method of  claim 1  wherein the biodiesel comprises methyl esters of tall oil fatty acids. 
     
     
       8. The method of  claim 1  wherein the biodiesel comprises esters of canola oil fatty acids. 
     
     
       9. The method of  claim 1  wherein the biodiesel comprises methylated soybean oil. 
     
     
       10. The method of  claim 1  wherein the biodiesel is derived from tall oil fatty acids. 
     
     
       11. The method of  claim 1  wherein the steam-assisted in situ bitumen recovery process is a steam-assisted gravity drainage (SAGD) process. 
     
     
       12. The method of  claim 1  wherein the steam-assisted in situ bitumen recovery process is a cyclic steam stimulation (CSS) process.